KR20240012625A - Manufacturing method of optical branched polyurethane polymer using non-toxic solvent - Google Patents

Abstract

The present invention relates to a method of producing a multifunctional branched polyurethane polymer containing hydroxyl and carboxyl groups and excellent optical properties using a non-toxic solvent. Despite the fact that polyurethane was synthesized using non-toxic solvents, breaking away from the existing method of synthesizing polyurethane using toxic organic solvents such as NMP, DMAc, and DMF, it has excellent adhesion and optical properties to difficult substrates without metals or reactive groups. It has shown the effect of realizing physical durability equal to or better than that of others.

Description

{Manufacturing method of optical branched polyurethane polymer using non-toxic solvent}

The present invention relates to a method for producing an optical branched polyurethane polymer using a non-toxic organic solvent, and more specifically, to a multifunctional branched polyurethane with excellent optical properties containing hydroxyl and carboxyl groups using a non-toxic organic solvent. It relates to a method of manufacturing polymers.

In general, polyurethane resin is a polymer compound that has a urethane bond in the molecule and is mainly synthesized through the reaction of diisocyanates and polyol compounds. It has excellent wear resistance, oil resistance, and solvent resistance, and has excellent elasticity. It is used in various fields such as adhesives, coatings, injection moldings, paints, inks, paints, foams, shoe parts, clothing, and medical polymers.

Conventionally, toxic organic solvents such as dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), and dimethylformamide (DMF) were mainly used to synthesize polyurethane resins, but they are used to improve consumer safety and workers' environment. As a result, attempts to synthesize polyurethane resin using non-toxic solvents from which toxic substances have been removed are continuing. For reference, whether or not it is a toxic substance is notified by the National Institute of Environmental Research.

Toxic organic solvents have good compatibility with water or organic solvents, so they are used as general solvents in many industrial fields. However, as eco-friendly issues are highlighted, rapid development of substitutes is urgently needed. Patent Publication No. 10-2014-0111038, which is a prior document, discloses that N-n-butylpyrrolidone, etc. can be used for a wide range of purposes, but the multifunctional branched form for optical use is obtained by polymerization between diol-based monomer and isocyanate. The method of synthesizing polyurethane polymer and its effects are not specifically disclosed.

Public Patent Publication No. 10-2014-0111038 (2014.09.17.)

As mentioned above, the first task of the present invention is to provide a method for producing a multifunctional branched polyurethane-based polymer using a non-toxic solvent instead of the toxic solvent mainly used to produce polyurethane polymers. The second task of the present invention is to provide a non-toxic polyurethane-based polymer composition that achieves adhesion to difficult substrates without metals or functional groups.

In order to solve the above problems, the present invention provides a method for producing a branched polyurethane-based polymer having excellent optical properties and having a multifunctionality of hydroxyl and carboxyl groups prepared through polymerization between a diol-based monomer and isocyanate in a non-toxic solvent.

According to one embodiment of the present invention, the non-toxic solvent is dipropylene glycol monomethyl ether (DPGMME), dipropylene glycol monoethyl methyl ether (DPGMEE), propylene glycol monomethyl methyl ether (PGME), propylene glycol monomethyl ether acetate ( PGMEA), N-ethyl-2-pyrrolidone (NEP), N-n-butylpyrrolidone, N-isobutylpyrrolidone, N-t-butylpyrrolidone, N-npentyl-pyrrolidone, N-(methyl- Substituted butyl)pyrrolidone, ring-methyl-substituted N-propyl and N-butyl pyrrolidone, and N-(methoxypropyl)pyrrolidone, diethyl formamide (DEF), water, ethyl acetate ( It is characterized by a mixture of one or two or more selected from EA), ethanol, isopropyl alcohol (IPA), and tetrahydrofuran (THF).

According to one embodiment of the present invention, the diol-based monomer is dimethylol propanoic acid or dimethylol butanoic acid.

According to one embodiment of the present invention, the isocyanate is toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, hexamethylene diisocyanate (HDI), 4,4-dicyclohexyl ethane diisocyanate (H ₁₂ MDI), 4,4-dicyclohexyl It is characterized by being one of ethane diisocyanate (IPDI).

According to one embodiment of the present invention, the polymerization includes the steps of 1) dissolving a diol-based monomer and an isocyanate in a non-toxic solvent to prepare a mixed solution; and 2) polymerizing the mixed solution while maintaining a temperature of 40 to 90°C; It is characterized by including.

Through one embodiment of the present invention, a branched polyurethane-based polymer with excellent multifunctional optical properties can be provided.

According to another embodiment of the present invention, 1 to 85% by weight of the polyurethane polymer of claim 5, 10 to 70% by weight of a non-toxic solvent, and 1 to 60% by weight of one or more additives among a neutralizer, wetting agent, and curing agent. It is possible to provide a composition containing.

The present invention provides a method for synthesizing polyurethane polymers that takes into account the environment and the safety of users and workers. In particular, the resin made by the manufacturing method of the present invention not only realizes physical properties equivalent to or better than those of resins manufactured using existing toxic solvents, but also exhibits excellent adhesion properties to metals and difficult substrates and has excellent optical properties to prevent changes in appearance due to aging. It can be minimized.

Additionally, the effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Since the description of the present invention is only an example for structural or functional explanation, the scope of the present invention should not be construed as limited by the examples described in the text. In other words, since the embodiments can be modified in various ways and can have various forms, the scope of rights of the present invention should be understood to include equivalents that can realize the technical idea. In addition, the purpose or effect presented in the present invention does not mean that a specific embodiment must include all or only such effects, so the scope of the present invention should not be understood as limited thereby.

The present invention relates to a multifunctional branched polyurethane polymer containing hydroxyl groups (-OH) and carboxyl groups (-COOH) with excellent optical properties and an environmentally friendly manufacturing method of the polymer.

As previously described, conventionally, toxic organic solvents such as dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), and dimethylformamide (DMF) were used as solvents for synthesizing branched polyurethane polymers.

The present invention deviates from this conventional method and synthesizes polyurethane using a non-toxic solvent. The polyurethane polymer is a multifunctional resin that is coated on a substrate, and then when volatile components are removed from the coated substrate, a thin resin film is formed. I do it.

Looking specifically, the polyurethane-based polymer synthesized using the non-toxic solvent of the present invention includes a polyurethane-based polymer produced through polymerization between a diol-based monomer and isocyanate.

The polyurethane-based polymer produced by the present invention is a branch-shaped polymer compound that is branched like tree branches and can have low viscosity, making it suitable for use as a coating resin.

First, we will explain the diol-based monomers participating in the reaction. Diol-based monomers having both a hydroxyl group (-0H) and a carboxyl group (-COOH) include dimethylol propanoic acid and dimethylol butanoic acid. At this time, the hydroxyl group provides properties that facilitate compatibility with solvents, and the carboxyl group provides properties that improve adhesion to the substrate.

In other words, while it is difficult for general organic substances to exert bonding force on a metal surface, the present invention can improve bonding force by strengthening the interaction with free electrons on the metal surface by using the planar three-dimensional structure of the carboxyl group and the resonance structure of the carboxyl group. there is. For the same reason, it has properties that can improve adhesion to difficult substrates that are difficult to bond to due to the lack of functional groups.

The isocyanates participating in the reaction include aromatic aliphatic and cyclic aliphatic isocyanates. Representative isocyanates include, for example, m-phenylene diisocyanate, 2,4- and/or 2,6-toluene diisocyanate (TDI), various isomers of diphenylmethane diisocyanate (MDI), hexamethylene-1,6 -Diisocyanate, tetramethylene-1,4-diisocyanate, cyclohexane-1,4-diisocyanate, hexahydrotoluene diisocyanate, hydrogenated MDI (H12 MDI), naphthylene-1,5-diisocyanate, methoxyphenyl -2,4-diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyldiphenylmethane-4,4 '-diisocyanate, 4,4',4"-triphenylmethane tri-isocyanate, polymethylene polyphenylisocyanate, hydrogenated polymethylene polyphenylisocyanate, toluene-2,4,6-triisocyanate, and 4,4'- Dimethyldiphenylmethane-2,2',5,5'-tetriisocyanate is included.

Next, we will explain non-toxic solvents. The non-toxic solvent has the same basic chemical structure as N-(methoxypropyl)pyrrolidone, optionally N-ethyl-2-pyrrolidone (NEP) in which the methoxy functional group is substituted with two carbons, N-n-butylpyrrolidone substituted by 4 carbons, N-isobutylpyrrolidone, N-t-butylpyrrolidone, N-n-pentylpyrrolidone substituted by 5 carbons, N-(methyl-substituted butyl) Pyrrolidone), ring-methyl-substituted (N-propyl or N-butyl) pyrrolidone, N-(methoxypropyl)pyrrolidone, etc. are suitable for use as substitutes for toxic solvents.

Other non-toxic solvents that can be used include dipropylene glycol monomethyl ether (DPGMME), dipropylene glycol monoethyl ether (DPGMEE), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), Ethyl formamide (DEF), water, ethyl acetate (EA), ethanol, isopropyl alcohol (IPA), tetrahydrofuran (THF), etc. can also be used.

As an example, in order to select a non-toxic solvent used in the synthesis of branched polyurethane among the non-toxic solvents, the solubility of the reactant was first evaluated. First, the solubility of various N-(methoxypropyl)pyrrolidone-type solvents in dimethylol propanoic acid or dimethylol butanoic acid was examined.

The solubility of the diol-based monomer introduced previously varies depending on the length of the methoxy functional group in N-(methoxypropyl)pyrrolidone. It was expected that the solubility would increase as the number of carbon atoms in the functional group increases, but it is actually more soluble at 3 or more carbon atoms. This fell. It is believed that when the entropy energy converges to 0, the longer the chain length becomes, the more difficult it is to expose the functional group due to entanglement, resulting in lower solubility.

In one embodiment of the present invention, the present invention will be described in more detail using an N-ethylpyrrolidone solution.

<Example 1>

Dimethylol propanoic acid and isocyanate were added to the reactor containing the N-ethylpyrrolidone solution, and the reaction was performed while stirring for 4 hours in the range of 40 to 90 ° C.

<Example 2>

Dimethylol propanoic acid and isocyanate were added to the reactor containing the N-ethylpyrrolidone solution, and the reaction proceeded with stirring at 60-90°C for 4 hours.

<Comparative Example 1>

Dimethylol propanoic acid and isocyanate were added to the reactor containing the DMAc solution, and the reaction proceeded with stirring at 60-90°C for 4 hours.

<Comparative Example 2>

Dimethylol propanoic acid and aliphatic isocyanate were added to the reactor containing the N-methylpyrrolidone solution, and the reaction proceeded with stirring at 60-90°C for 4 hours.

<Comparative Example 3>

Dimethylol propanoic acid and aromatic isocyanate were added to the reactor containing the N-methylpyrrolidone solution, and the reaction proceeded with stirring at 60-90°C for 4 hours.

After the reaction, it was confirmed through infrared spectroscopy (FT-IR) that the NCO peak disappeared in all samples, meaning that the polyurethane synthesis reaction was completed. The viscosity of the composite was evaluated using the KS M ISO2555 method and the results are shown in Table 1. Adhesion to the substrate was tested using the KS M ISO16276-2 method and the results are shown in Table 1.

Additionally, the optical properties of the composite defined the color of the resin under the condition of 20 wt.% solid content after synthesis, which was expressed as Gardner value according to ASTM D1544 standard. Among the optical properties of the composite, yellowing was determined using the difference (△ YI = YI - YI ₀ ) before exposure ( YI ₀ ) and after exposure ( YI ) using the KS M 3026 method, and the results are similarly shown in Table 1.

Table 1. Adhesion, viscosity, and optical properties test results of examples and comparative examples Adhesion viscosity optical properties PET film Al foil m.pas Transmittance/Haze Color(G) Yellowing (△ YI ) Example 1 0 ratings 1st grade 10~30 Above 90/Below 1.0 One 0 Example 2 0 ratings 0 ratings 20~50 Above 90/Below 1.0 One 0 Comparative Example 1 0 ratings 0 ratings 20~50 Above 90/Below 1.0 One 2 Comparative Example 2 0 ratings 0 ratings 20~50 Above 90/Below 1.0 3~4 2 Comparative Example 3 0 ratings 0 ratings 20~50 Above 90/Below 1.0 4~5 3

Referring to Table 1, it can be seen that in Example 1, the adhesion to the metal (aluminum) substrate was grade 1, which was slightly lower than that of Example 2. This is believed to be due to a decrease in the degree of polymerization of the polyurethane-based polymer due to unreacted isocyanate due to relatively low-temperature polymerization conditions, resulting in a difference in physical properties.

However, it was confirmed that Example 2, which was carried out at a higher reaction temperature, exhibited equivalent or better physical properties and behavior when compared to Comparative Examples 1, 2, and 3 synthesized using toxic solvents. In particular, in terms of optical properties, when comparing Examples 1 and 2 with Comparative Examples 1, 2, and 3, there was no significant difference in transmittance or haze, but color (G) and yellowing characteristics (△ YI ) were compared to those of the examples of the present invention. It was confirmed that they were excellent.

As a result, it can be confirmed that the branched polyurethane polymer prepared according to the manufacturing method of the present invention not only has excellent adhesion and durability to difficult substrates or metals that do not contain a reactive group, but also has superior optical properties compared to the comparative examples. there was.

On the other hand, based on the total weight of the composition, 1 to 85% by weight of the branched polyurethane polymer prepared through the present invention, 10 to 70% by weight of a non-toxic solvent, and any one or two or more of a neutralizer, a wetting agent, and a curing agent are mixed. The composition containing from 60% by weight can be used in the production of adhesives, coatings, injection moldings, paints, inks, paints, foams, shoe parts, clothing, medical polymers, etc.

The non-toxic solvent contained in the composition may be used by mixing one or two or more of the solvents used in the production of the branched polyurethane-based polymer described above.

In addition, additives such as neutralizers, wetting agents, and curing agents are materials commonly used in polymer production. For example, amine-based additives for water dispersion of the polymer, adjust the surface tension of the composition to increase affinity with the substrate and improve dispersibility. Additives for adjusting surface tension that strengthen and enable uniform application, heat-curing or UV-curing type curing or curing accelerator additives to improve the mechanical properties or durability of the applied film, but are not limited thereto.

Although the present invention has been described above with reference to an embodiment of the present invention, those skilled in the art can modify the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the claims below. and that it can be modified.

Claims (7)

A method for producing a branched polyurethane-based polymer with excellent optical properties and having a multifunctionality of hydroxyl and carboxyl groups prepared through polymerization between a diol-based monomer and an isocyanate in a non-toxic solvent. According to paragraph 1,
The non-toxic solvents include dipropylene glycol monomethyl ether (DPGMME), dipropylene glycol monoethyl ether (DPGMEE), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), and N-ethyl-2- Pyrrolidone (NEP), Nn-butylpyrrolidone, N-isobutylpyrrolidone, Nt-butylpyrrolidone, Nnpentyl-pyrrolidone, N-(methyl-substituted butyl)pyrrolidone, ring -Methyl-substituted (N-propyl or N-butyl) pyrrolidone, N-(methoxypropyl)pyrrolidone, diethyl formamide (DEF), water, ethyl acetate (EA), ethanol, A method for producing a branched polyurethane-based polymer with excellent multifunctional optical properties, characterized in that one or two or more selected from isopropyl alcohol (IPA) and tetrahydrofuran (THF) are mixed. According to paragraph 1,
A method for producing a branched polyurethane-based polymer with excellent multifunctional optical properties, wherein the diol-based monomer is dimethylol propanoic acid or dimethylol butanoic acid. According to paragraph 1,
The isocyanate is any one of toluene 2,4-diisocyanate, toluene 2,6-diisocyanate, hexamethylene diisocyanate (HDI), 4,4-dicyclohexyl ethane diisocyanate (H ₁₂ MDI), and 4,4-dicyclohexyl ethane diisocyanate (IPDI). A method for producing a branched polyurethane-based polymer with excellent multifunctional optical properties. According to paragraph 1,
The polymerization includes the steps of 1) dissolving a diol-based monomer and isocyanate in a non-toxic solvent to prepare a mixed solution; and 2) polymerizing the mixed solution while maintaining a temperature of 40 to 90°C; A method for producing a branched polyurethane-based polymer with excellent multifunctional optical properties, comprising: A branched polyurethane-based polymer with excellent multifunctional optical properties prepared by the method of any one of claims 1 to 4. Based on the total weight of the composition,
1 to 85% by weight of the polyurethane-based polymer of claim 6;
10 to 70% by weight of a non-toxic solvent; and
A composition comprising 1 to 60% by weight of an additive containing one or more of a neutralizer, a wetting agent, and a curing agent.